The effects of oxygen concentration on ultraviolet luminescence of ZnO films by sol–gel technology and annealing

• Published in: Journal of sol-gel science and technology 2008-07, Vol.47 (1), p.1-6
• Main Authors: Hsieh, P. T., Chen, Y. C., Lee, M. S., Kao, K. S., Kao, M. C., Houng, M. P.
• Format: Article
• Language: English
• Subjects: Annealing; Atomic force microscopy; Ceramics; Chemistry; Chemistry and Materials Science; Colloidal gels. Colloidal sols; Colloidal state and disperse state; Composites; Exact sciences and technology; Excitons; General and physical chemistry; Glass; Inorganic Chemistry; Luminescence; Materials Science; Microscopy; Nanotechnology; Natural Materials; Optical and Electronic Materials; Original Paper; Oxygen; Photoelectrons; Photovoltaic cells; Radiative recombination; Scanning electron microscopy; Silicon dioxide; Silicon substrates; Sol-gel processes; Thickness; Thin films; X ray photoelectron spectroscopy; X-ray diffraction; Zinc oxide
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-008-1747-7

ZnO thin films were successfully deposited on SiO 2 /Si substrate using the sol–gel technique and annealed in various annealing atmospheres at 900 °C by rapid thermal annealing (RTA). X-ray diffraction revealed the (002) texture of ZnO thin films. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that the grains of the ZnO thin film were enlarged and its surface was smoothed upon annealing in oxygen. PL measurement revealed two ultraviolet (UV) luminescence bands at 375 and 380 nm. The intensity of the emission peak at 380 nm became stronger as the concentration of oxygen in the annealing atmosphere increased. The X-ray photoelectron spectrum (XPS) demonstrated that a more stoichiometric ZnO thin film was obtained upon annealing in oxygen and more excitons were generated from the radiative recombination carriers consistently. Additionally, the UV intensity increased with the thickness of ZnO thin film.